class Queue:
    def __init__(self):
        self.list=[]

    def is_empty(self):
        return len(self.list)==0

    def size(self):
        return len(self.list)

    def peek(self):
        return self.list[0]

    def poll(self):
        head=self.list[0]
        del(self.list[0])
        return head

    def offer(self,a):
        self.list.append(a)

if __name__=="__main__":
    queue=Queue()
    queue.offer(11)
    queue.offer(22)
    queue.offer(33)
    queue.offer(44)
    print(queue.size())
    print(queue.peek())
    print(queue.poll())
    print(queue.poll())
    print(queue.poll())
    print(queue.poll())
    print(queue.is_empty())
